The Belgian avant-garde composer Henri Pousseur, who has died aged 79, possessed an extraordinarily complex but undogmatically creative mind. Highly regarded in his own country and widely acknowledged in the Netherlands and Germany, he was less well known in France and hardly at all in Britain, with two notable exceptions.

In 1978, he accepted a major commission from the newly formed electro-acoustic vocal quartet Electric Phoenix. The resulting half-hour marathon, Tales and Songs from the Bible of Hell, would shape the group's technology and aesthetics for years to come. From 2004, he worked with the Lansdown Centre for Electronic Arts at Middlesex University, north London, to develop a digitised version of Scambi (Exchanges), an unorthodox "open form" tape-music composition that he had constructed as early as 1957.

Although Pousseur had long been associated with the largely serialist composers of the Darmstadt summer music school in the 1950s, and those of the contemporary music festival at Donaueschingen, both in west Germany, from 1960 he set out to explore a unique philosophical, aesthetic and compositional landscape. At a time when the avant garde was declaring its total liberation from every musical convention, he was already going beyond the new straitjacket of serialism to imagine and construct a methodology in which the audience could participate. In 2004, he was still looking forward: "I think composition will not always be the production of closed and finished objects which one can buy and sell ... We will have to think increasingly in a collective way ... In fact this has always been the case."

Pousseur's own collectivity looked backwards as well as forwards. He was an enthusiastic practitioner of musical collage at a time when it was highly unfashionable. The musical structure of Tales and Songs was based almost entirely on John Dowland's early-17th-century air, Flow My Tears, though often transformed beyond recognition. In the accompanying pre-recorded tape, which I assembled in accordance with meticulously detailed instructions, a single phrase could be lowered four octaves to provide a drone, or re-recorded several times, cut into tiny fragments, randomly re-spliced and spooled at high speed across the tape heads to create an accelerating frenzy. Thus the work becomes at times a simultaneous, multilayered theme-and-variations.

During the last years of his life, Pousseur was to suffer from an illness that might have been conceived by an ironic demon. Acute hyperacusis converted the musical sounds that he had manipulated all his life into an excruciating torment, and so he set out to work with images, for which he was obliged to learn a whole new aesthetic and technological discipline. "I laboured for a year-and-a-half or so, honing my craft and adopting a visual language that I felt was seldom explored."

The result was Village Planétaire Vu de Nivelles, "a 16-hour programme designed to inhabit the inner courtyard of an architectural complex built by Philippe Samyn in the north of this Belgian city". The sonic element was to consist of a spatially distributed soundtrack assembled by Pousseur's son Denis from "my rather flexible designs and my choices of samples of traditional music, coming from the entire world".

But it is the extraordinary visual images that transport the work into a new and magical universe. Pousseur's ambition was to achieve "a sort of painting in continuous transformation ... [including] virtual lateral movements suggested by the images themselves ... such as birds in flight or the beating of drums, which the music brings to life, or more abstract forms such as wave undulations which come close to handwriting". We have become cynically accustomed to the razzle-dazzle visual transformations in television commercials, but what sets Pousseur's images in a space of their own is the fact that they are not calculated to sell us useless junk, but are the spontaneous gift of a complex and generous intelligence. In other words, they are art.

The unifying force bringing the musical and visual elements together was, according to Pousseur, his long-time collaborator, the French philosopher/novelist Michel Butor. The latter "not only helped me to devise the titles of the 16 Paysages, each expressing the commonality of the evoked Earth's regions ... but also wrote a massive, isomorphic poem of the same name", which was incorporated into the soundtrack. The end result was to be a spatial/visual/aural construct in the tradition of the 1958 Philips Pavilion for the World's Fair in Brussels by Xenakis/Corbusier/Varèse. If it ever comes to fruition, it would make a stunning interactive DVD.

In addition to a lifetime of teaching, Pousseur's output included almost 200 compositions, several books and many articles. All of these are listed and described on his website, henripousseur.net. Many pages of interviews and programme notes concerning Scambi and Village Planétaire Vu de Nivelles are posted on the Lansdown Centre website, scambi.mdx.ac.uk/documents.html. Pousseur's long association with Electric Phoenix will soon be documented on their new website.

He is survived by his wife Théa, whom he married in 1954, and his children Isabelle, Denis, Marianne and Hélène.

• Henri Pousseur, composer, author and teacher, born 23 June 1929; died 6 March 2009